A standard used in asynchronous transfer mode (ATM)-based networks is G.983. The G.983 standard supports three wavelengths: a 1490 nm downstream basic band, a 1550 nm downstream enhancement band, and a single 1310 nm upstream signal. FIG. 1 shows a standard G.983 optical transmission. The transmission is partitioned into symbol periods (as shown on the time axis) generated by a transmission system clock based on a data rate for communication. Each of the symbol periods represents either a binary “0” (a dim optical intensity) or a binary “1” (a bright optical intensity).
Upgrading standard G.983.1-based networks to IP-based Passive Optical Network (PON) networks typically requires a complete replacement of the optical network terminations (ONTs) and the optical line terminal (OLT). Upgrades to the OLT can be feasibly planned. However, replacing all of the ONTs may require taking an entire multipoint network out of service.
Accordingly, there is a need for an improved method and system of upgrading ATM networks to carry IP traffic.